Twcmanager

* Dropped the default policy check timer down to 30 seconds from 60 seconds after positive feedback on lower calculation intervals
* Dropped cache time in all EMS modules down to 10 seconds to ensure that the lower calculation intervals work correctly
* Added ability to override the policy check timer to set it to any value desired
* Added ability to override the policy entirely from the configuration file (with caveat that this is not recommended)
* Added ability to extend the policy at two points (before and after) to add extra rules in whilst retaining the rest of the policy
* MQTT control command chargeNow will now accept a payload specifying the number of amps and duration to charge
* Added support for remote debugging using the Python Visual Studio remote debugger (ptvsd) (thanks MikeBishop)
* Significant improvements to Powerwall2 EMS module including authentication fixes, addition of Operating State to module state tracking, fixing a HTTPS certificate validation issue and stability testing (thanks MikeBishop)
* Early framework for centralised module instantiation
* Allow use of module parameters within policy rules (thanks MikeBishop)
* Added setup.py setuptools script, which will shortly become the recommended installation method
* Bugfixes
* Fixed an issue where the policy based charging rules could not access settings variables due to an error in string offset (thanks AndySchroder).
* Fixed a bug with debug output if the charger is configured to draw more amps than the wiring can handle (thanks AndySchroder).
* Fixed an issue with the debug web interface (WebIPC) which impacted sending custom commands to the TWC and recieving the result
* Fixed the refresh image for the IPC web interface (thanks notreallybob).
* Fixed a situation where amp calculations can lead to a value of -1 due to previously used default values. Any amp related defaults are now 0, with exception handling for negative values.
* Fixed an error in policy rule where green energy charging was offset by 1 hour (thanks MikeBishop)
* Fixed Powerwall2 authentication process (using cookies rather than Authorization header) (thanks MikeBishop)

* Implement policy-based charging, where individual charging logic (for scheduled, non-scheduled, green energy and charge now logic) is now centralised.
* Benefits of this approach:
* Single point within the code where we set the amps to share.
* Defined priority to ensure one case does not override another.
* Lays foundation for future advanced use cases.
* TeslaAPI: Add optional override to not instruct a vehicle to stop charging via Tesla API (if the policy would otherwise dictate this) if the vehicle SOC is below a defined (optional) minimum. This avoids excessive battery drain which may be harmful to the vehicle's battery. Instead of stopping the charge session, the vehicle will continue to charge at minAmpsPerTWC until minimum SOC is met (thanks MikeBishop).
* Powerwall2 EMS: Feature to limit charging when Powerwall2 state of charge is below a defined minimum, to avoid depleting Powerwall2 during low energy generation (thanks MikeBishop).
* Bugfix: HASS EMS module was non-functional due to an error introduced during config separation. Fixed in v1.1.6.
* Bugfix: Makefile update to install php7.3 on raspbian (thanks MikeBishop)
* Bugfix: Fix typo which did not set desiredAmps to 0 when total amps available for all chargers was less than 1 (thanks MikeBishop)
* Bugfix: Fix crash condition in dumpState function for WebIPC control interface (thanks MikeBishop)
* Bugfix: Correctly display multiple chargers in web (RPC) interface (merged from upstream cdragon)

* Standardised module configuration handling (which helps reduce the number of exceptions related to configuration)
* Added configuration to enable/disable and configure HTTPControl module
* Added Grid Status, Voltage and Password Authentication support to Tesla Powerwall2 EMS module
* Tested and fixed TWCManager Slave Mode functionality

* Implemented Tesla login / token retrieval for HTTP Config module.
* Improved debug logging for Tesla API Vehicle module.
* Modularised the Web IPC interface for the external web server control component.
* Fix: Status output now subtracts charger load from consumption.
* Re-implemented the Tesla API queries using python's request module rather than external shell calls to curl. Provides better exception handling and less shell command/subprocess interaction.
* Breaking Change: Improved Settings Storage for non-volatile settings (not configuration) storage.
* This will require a manual port of the settings from /etc/twcmanager/TWCManager.settings to /etc/twcmanager/settings.json
* Due to a small user base, this is not done automatically. If there is demand for a port method, an issue can be raised for a feature request, and I'll create a one time script to port old settings to new settings.

* Added new HTTP Control Module for (limited) in-built HTTP control of TWCManager.
* Added new Tesla Powerwall 2 EMS module for solar/consumption tracking.
* Separation of Slave TWC code from Master TWC code - this adds stability by r
emoving a large number of global variables and reduces complexity for future fea
ture improvements.
* Please Note: This is a major structural change to TWCManager, and is expected to take some time to fully test and validate. A benefit of this change is that now TWCSlave is modular, we can fully implement modular control interfaces.

* Improvements to HomeAssistant EMS module to avoid setting Consumption/Generation values to zero as a result of a connection failure, and better exception handling in general for the module.
* Added EMS support for TED (The Energy Detective)
* Added Control module support with a first control module for MQTT, with initial commands to stop the TWCManager daemon and start charging immediately.
* Improvements to the MQTT and HASS topic/sensor names for Slave TWCs. (4 byte instead of 2 byte)